Nanoliter Array Loading - Patent 8105554

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Nanoliter Array Loading - Patent 8105554 Powered By Docstoc
Description: The invention generally relates to techniques for assaying sample liquids, and more specifically to techniques for utilizing a sub-set of nanoliter sample volumes in an array.BACKGROUND ART Various systems are known for performing a large number of chemical and biological storage assays and synthesis operations. One approach uses an assay chip having an array of nanoliter volume through-hole sample wells with hydrophilic interiorsand openings surrounded by hydrophobic material. One specific commercial example of a nanoliter chip system is the Living Chip.TM. made by BioTrove, Inc. of Woburn, Mass. Nanoliter chip technology relies on the ability to handle very small volumes offluid samples, typically, 100 nanoliters or less. The various considerations taken into account in handling such small liquid samples are known as microfluidics. FIG. 1 shows a cut away view of a typical nanoliter sample chip. This is described, for example, in U.S. Pat. No. 6,387,331 and U.S. Patent Application 20020094533, the contents of which are incorporated herein by reference. Array chip 10contains an array of through-hole sample wells 12 that traverse the chip 10 from one planar surface 14 to the other opposing planar surface (not shown). The sample wells 12 may be grouped into sub-arrays such as by controlling the spacing between the wells. For example, FIG. 2 shows a chip 10 in which the sample wells 12 are grouped into a 4 by 12 array of 5-well by 5-well sub-arrays 20. Inanother embodiment, the sub-arrays 20 may be 8-wells by 8-wells or any other convenient number. The chip 10 in FIG. 2 is 1''.times.3'' to correspond to a standard microscope slide. The sample wells 12 in a sub-array 20 may be laid out in a square orrectangular grid arrangement as shown in FIG. 2, or the rows and/or columns of sample wells may be offset as shown in FIG. 1. The sample chip 10 typically may be from 0.1 mm to more than 10 mm thick; for example, around 0.3 to 1.52 mm thick, and commonly 0.5